Ukraine's former prime minister Yulia Tymoshenko in court. Her daughter says she is being mistreated in prison. Photograph: Sergei Supinsky/AFP/Getty Images

The daughter of jailed former Ukrainian prime minister Yulia Tymoshenko has accused prison authorities of subjecting her mother to "horrendous" pain by denying her painkillers.

Tymoshenko is serving a seven-year term after a trial the west condemned as being politically motivated.

Eugenia Tymoshenko told reporters on Thursday that her mother, who complains of severe back pain, has been deprived of painkillers for several days. She claimed prison doctors were mistreating and misdiagnosing her mother, who will be examined by Canadian and German doctors next week.

Tymoshenko, who was convicted in October on charges of abuse of office, accuses President Viktor Yanukovych of orchestrating the charges to get rid of a rival. Tymoshenko lost the last presidential race to Yanukovych.